An experimental investigation of the application of Photocatalysis, an advanced oxidation (AO) method, for the disinfection of cyanobactieria (blue-green algae) was carried out.

Blue-green algae blooms can be harmful to humans and animals, posing a serious public health threat. Blooms also dramatically reduce our ability to enjoy the recreational opportunities of lakes and rivers. Some blue-green algae produce natural toxins or poisons. When these algae die and break down, toxins are released into the water. If animals ingest the toxin, they can be quickly paralyzed and/or die. Furthermore, there are currently no recognized methods for the disinfection of cyanobacteria found in water bodies. The only option is to reduce and/or eliminate the source of nutrients that allows it to grow so abundantly.

Tests were carried out by exposing glaucocystis nostochinearum to UV radiation and semiconductor titanium dioxide (TiO₂) as catalyst for a period of 1 hour.  Results show that more than 60% of the colonies studied were eradicated after 1 hour exposure and disinfection followed a first order reaction kinetics. However, we observed that removal of TiO₂ after its application in the slurry form will pose another problem, due to its fine particle size. Hence the need to immobilize TiO₂ and test its effectiveness on the disinfection of cyanobacteria in future studies. This investigation enables us to confirm that the application of photocatalysis for blue-green algae disinfection is feasible.